Expected value with empirical probabilities

Find expected value based on empirical probabilities.

Problem

Sal is working on the customer service of the restaurant that he owns. He recently asked 100 customers how many ice cubes they prefer in their drink. The results of this survey are shown in the table below.
Plot points to represent the expected sum of the quantity of ice cubes for each number of randomly selected guests.
Ice cubesGuests
050
120
210
320
Total100